Inhibitory Activity of Chemical Constituents from Vitellaria paradoxa Gaertn. (Sapotaceae) Against Pathogens Associated with Respiratory Tract Infections

Abstract

Vitellaria paradoxa Gaertn. is a commonly used medicinal plant for the treatment of tuberculosis (TB) and other respiratory infections in Africa. Therefore, its phytochemicals can be explored in rational drug discovery, development, and design against respiratory-tract infections. The aim of this study is to identify chemical composition of V. paradoxa hexane stem-bark extract, and further isolate possible antimicrobial agents from its crude extract. 48 phytochemicals, including1-heptacosanol, 2-nonenal, (E)-, and hexadecanoic acid, methyl ester were identified using GC-MS. Column chromatography led to the isolation of three compounds, including 11-hydroxy β-amyrin cinnamate (1), α-amyrin cinnamate (2), and sitosterol cinnamate (3). All the compounds showed activity against all the tested pathogens, with compound (3) showed better activity against all bacterial strains, with minimum inhibitory concentrations (MICs) varying from 0.0625 to 0.25 mg/ml. Compounds (1) and (2) showed no cytotoxicity against the cervical cancer cell line (HeLa) (IC50; 82.53 ± 4.07 and 77.82 ± 10.5 respectively). To our knowledge, compounds 2 and 3 are reported here from the stem-bark part of the plant for the first time. Similarly, inhibitory activities of compounds 1–3 against the tested strains are studied here for the first time. These results provide in part scientific justification for the traditional uses of V. paradoxa for treating respiratory tract infections, including tuberculosis in Africa.